Analysis of Arc-Jet Tile Calibration Tests in the PTF: Compression-Pad Surface Heating Distribution

摘要

Tile calibration tests are conducted in the NASA Ames 20 MW Panel Test Facility to characterize the surface heating distribution of a compression-pad test article, which contains two circular recessed cavities, a cavity within a cavity. The arc-jet test data include measurements of surface pressure and heat flux on a water-cooled calibration plate, and measurements of surface temperatures of the reaction-cured glass coated tile plates. Both flat and compression-pad contoured tile plates instrumented with surface thermocouples are tested to measure heating augmentations at various locations on the cavities and to provide hot-wall calibration data for the compression-pad tests conducted earlier. Computational fluid dynamics simulations are performed to characterize the arc-jet test environment and estimate its parameters consistent with the facility and calibration measurements. The present analysis comprises simulations of the nonequilibrium flowfield in the facility nozzle, test box, and flowfield over test articles. Both laminar and turbulent simulations are performed, and the computed results are compared with the experimental measurements. Both computations and test data show that the contoured tile plate surface heating distribution changes with the plate deflection angle. These results are consistent with the earlier finding that the flow is transitional at the test conditions of interest.